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在专题图件、实测土壤数据以及GIS与RS技术的支撑下,研究新疆天山南麓渭干河平原1980年到2001年绿洲景观变化及其对土壤性状的影响。结果表明,20年来区内以耕地为主体的人工绿洲景观面积大幅增加,天然绿洲和荒地面积减少,水域和荒漠面积略有增加;人工绿洲面积扩展的主要供体为荒地和天然绿洲,共有31 8%的天然绿洲和35 1%的荒地转化成人工绿洲,人工绿洲的9 9%和2 2%退化为荒地和荒漠景观;天然绿洲转化为人工绿洲,土壤有机质、全氮、碱解氮、速效磷和速效钾分别下降了51 0%、42 6%、7 2%、43 2%和44 9%;荒地转化为人工绿洲,有机质、全氮和速效钾各自减少了3 1%、12 9%和12 6%,碱解氮和速效磷则提高了25 9%和16 7%。人工绿洲的扩展导致土壤养分在总体上呈下降趋势。此外,绿洲景观的变化对土壤含水量和土壤含盐量也产生较大的影响。
With the help of thematic maps, measured soil data and GIS and RS technologies, this paper studies the oasis landscape change and its effect on soil properties in the Weigan River plain in the south of the Tianshan Mountains in Xinjiang from 1980 to 2001. The results showed that in the past 20 years, the area of man-made oases with arable land as the main body increased greatly, the areas of natural oasis and barren land decreased, and the area of water and desert land increased slightly. The main oases of man-made oasis area were abandoned land and natural oasis. 8% of the natural oasis and 35.1% of the wasteland were transformed into artificial oases. Ninety-nine percent and twenty-two percent of the artificial oases degraded into wasteland and desert landscapes. The natural oases were transformed into artificial oases, soil organic matter, total nitrogen, available nitrogen, Available phosphorus and available potassium decreased by 51 0%, 42 6%, 72%, 43 2% and 44 9% respectively. The conversion of wasteland to artificial oasis decreased by 31%, 12 9% and 12 9% respectively % And 12 6%, respectively, while available nitrogen and available phosphorus increased 25 9% and 16 7% respectively. The expansion of artificial oases resulted in a general downward trend in soil nutrients. In addition, changes in oasis landscape have a greater impact on soil moisture content and soil salinity.